NEET Class neet Answered

(i) Diaphragm contracts to help in (1) inspiration while the contraction of abdominal muscles helps in (2) forced expiration.

(ii) Vital capacity of trained athletes is (3) higher than that of non-athletes while the vital capacity of non-smokers is (4) higher than that of smokers.

(iii) Alveolar PO₂ is (5) higher than the venous PO₂ while arterial PO₂ is (6) lower than the alveolar PO₂.

So, the correct answer is option c : (1)-inspiration, (2)-forced expiration, (3)-higher, (4)-higher.